Regenerative furnace



E. E. MILNER REGENERATIVE FURNACE Sept. 30, 1941.

Filed Oct. 21, 1940 2 Sheets-Sheet 1 Fla. 7

FIG. 8

INVENTOR. EDWIN E. MILNER FIG. 6

ATTORNEY.

p 30 1941- E. E. MILNER 2,257,392

REGENERATIVE FURNACE Filed Oct. 21, 1940 2 Sheets-Sheec 2 ZNVENTOR.

55mg! E. MILNER ATTORNEY,

Patented Sept. 30, 1941 [A UNITED STATES PATENT OFFICE monunn fm runuacaI J Edwin E. Milner, Muncie, Ind.

ApplicationOctober 21, 1940, Serial N0.362,022

2 Claims. (01. 263-51) This invention relates to improvements infurnaces of the gas burning type, in connection with which is used aregenerator in which the incoming air or gas is heated by contact withmasses of brickor the like previously heated by the outgoing hot air orwaste gases. The invention has especial reference to regeneratorconstruction intended to be used in connection with a furnace or meltingchamber of the general form as used intheindustry of glass making. Afavored type of regenerator as applied to a furnace of the abovedescription, and which is known as the checker brick system or setting,includes a chamber whose walls and crown are constructed of refractoryunits, said chamber being directly coordinated with the melting chamber.In the interior of such chamber, checker bricks such as of therectangular form as shown in the drawings, are arranged in spaced order,and in such alignment, that there is provided a system of longitudinal,transverse, and vertical passageways. By this arrangement there ispermitted the free passing of the waste gases to the chimney, and at thesame time there is such absorption of heat units from said waste gases,that there is preheating of the air entering the regenerator either ofthese subterfuges of course affects the entire furnace operationadversely. Other accepted facts are, that the volume of air and gas(combustibles) introduced into the combustion chamber is determined inaccordance with the volumeof waste gases whichthe regenerator has thecapacity to handle; and ,that while the checker setting should sofunction as to permit passing of the waste gases in proper volume and atproper velocity, it hould also so function as to retain the heatunitscontained in said passing gases.

Dueto the fact that most waste gases contain that the exposed surfacesof the bricks become so coated, and the coating takes such form, thattheir surfaces are rendered rough and irregular,

and they are so distorted in form that the areas of the passageways aredecreased and distorted within a relatively short period of time. As aresult, the circulation of currents through the chamber is so impeded,that maintenance of ignition temperatures in the combustion chamber isadversely and seriously affected, Augmenting of the chimney draft toincrease velocities; cleaning the bricks; and replacing those toodeformed for re-use; results in delay and in such interruption ofoperation, that the campaign of the furnace is definitely arrested.

Many improvements have been made in the melting chamber structure. suchas improved refractories, insulation, automatic control, and artificialcooling, the factremains however, that the regenerative chambers, forlack of uniform eillciency, cause the entire furnace apparatus to becomelnefllcient. Although means of divers kinds have been resorted to inefforts to remove from the checker bricks, the coatings and depositsabove referred to, such means have been of doubtfulvalue for the reasonthat by the very nature of the checker brick system, the exposedsurfaces are only partly accessible to lancing and blasting operations;and moreover, vigorous efforts in attacking the surfaces of the bricksare not permissible, by reason of the danger of fracture, and of thedislodging of the bricks.

To make possible the full enjoyment of advantages which are incident tothe improvements generally that have been developed in the manufactureof refractories used in the construction and adaptation of thecombustion chamber comprised in regenerator furnace installations of thetype herein described, my invention has proceeded upon the broad conceptof providing regenerator chamber construction embodying features wherebyimproved current movement and may be minimized if not eliminated, andwhereparticles in suspension, and also condensible vapors, a seriousdifficulty experienced in the use of regenerator settings as hithertodevised is,

by maximum absorption of heat units from the passing ases may beobtained. Further aims of my invention are to afford regenerator chamberconstruction which will lend itself to facility in cleaning, and whichat the same time will be strong and durable, economical of manufacture,and capable of being installed by the exercise of only ordinary skill.

My invention consists of a regenerator instal-' lation comprising bricksof conventional rectangular formation spaced, and arranged in alignmeatone row above another. each brick of one row being in offset relation toeach brick of the adjacent row, and transverse tie bricks eachbefractory unit of spool shaped construction, the

wall thereof being concav and each embodying a stud, the ends and thestuds of said tie brick being adapted to engage the proximate sides andthe facing ends respectively of conventional bricks aligned for achecker setting.

Figure 1 is a side view of my improved tie brick for checker settings ofregenerator chambers of the class described.

Figure 2 is an end view, in the direction of arrow 2 in re 1.

Figure 3 is a view taken arrow 3 in Figure 1.

Figure 4 is a central longitudinal sectional view taken on line 44 inFigure 2, in the direction of arrow 4.

Figure 5 is a cross section view taken on the line 5-5 in the directionof arrow 5 in Figure 1.

Figure 6 is a diagrammatic view, partly in cross section, showing atypical regenerative furnace installation, and which is, illustrative ofthe general structure and relative positions of the regenerativechambers.

Figure 7 is a horizontal sectional plan view of a conventional checkerbrick setting, and in a regenerative chamber of the form shown inFigfigure 8 is a vertical cross section view of a checker brick setting,as in a regenerative chamber of the form shown in Figure 6.

Figure 9 is a horizontal sectional plan view showing the appearance of achecker brick setting wherein my invention is embodied.

Figure 10 is a vertical cross section view, on the broken line ifll9, inthe direction of arrow I! in Figure 9.

Figure 11 is a vertical longitudinal cross section view, on broken linell--| I, in the direction of arrow II in igure 10.

Figure 12 is a vertical longitudinal section view, on the broken linel2-I2, in the direction of arrow I! in Figure 10.

Figure 13 is a modified form of installation.

Figure 14 is a modified form of installation.

My improved tie brick is shown herein, in the form and contour preferredfor installations therein the line bricks used are of the conventionalrectangular type, and which are about nine inches in length, four andone half inches high, and two and one half inches thick. It will beunderstood of course that references herein to dimensions are merely forthe purpose of easily making clear the facility with which my improvedtie brick is coordinated with the conventional bricks in constructingthe checker setting.

For a setting in which the rectangular bricks of the above dimensionsare used, my new tie brick unit A is six and one half inches in length,out to out, of flanges B. It is circular in cross section, and consistsof refractory material molded into spool shaped formation, the sidesthereof being concave. Each end of said unit embodies a stud C which inthe present instance is four in the direction of v and one-half inchesin length, two and one-half inches in width, and one inch in depth. Myimaasasoa proved tie brick is capable of being formed by the practice ofmolding, such practice being common in the making of structural unitscomposed of refractory material. The nature and quality of the materialof which the brick is composed is determined, by the duty which is to beimposed upon it. For the duty imposed wherein it is used in theinstallation of a setting for a regenerator chamber used in connectionwith a glass melting furnace, a composition of high alumina content isrecommended same being preferred for high temperature operation.Obviously, the material of which the brick is composed should besuitable to constitute a brick especially adapted to the requirements itis intended to meet.

In observing the views in Figures 9, 10, 11 and 12, which areillustrative of regenerative chamber installations wherein my inventionis embodied, and my improved tie bricks are employed, the business ofinstalling the checker setting will readily be understood. Line bricksK, L and L are disposed on the floor of the chamber, and in thepositions spaced as shown. on top of these line bricks L and L, are nowdisposed line bricks M and M, spaced as shown, and each being in offsetrelation to the adjacent underlying brick. My improved tie bricks A arenow disposed in position, each with its stud C in the space between theends of the bricks M and M, this business continuing until the floorarea and interior of the chamber will have been filled.

The manner in which the flanges B of the tie bricks engage the sidefaces of the ends of the line bricks, and the manner in which the studsC are received in the space between the facing ends of the line bricks;and the manner in which the intermediate portions of the top and bottomfaces of the line bricks engage the top and bottom edges of the saidstuds C, will be clearly understood by referring to the said viewsFigure 9, Figure 10, Figure 11 and Figure 12.

My new tie brick so lends itself to the purposes described, that variousselections, as to which of the spaces in which the studs C are to beplaced and retained may be had, thereby rendering possible the varyingof the number of passageways or flues. This variation may cover more orless wide range, in conformity with the volume, temperature, andcharacter of the gases entering and leaving the regenerative chamber.

Recommendations are that in instances where the waste gases are freefrom particles in suspension, the setting of the tie bricks is forsmaller passageway areas. In instances where the gases are highlycontaminated, the setting of the tie bricks is for larger passageway orflue areas.

Whereas in all instances, my new tie brick is the same in character andform, its selection as to sizeis governed by the size of the line brickbeing used, the height of the stud of the tie brick in all instancesbeing the same as the height of the line brick in combination with whichit is used.

In Figure 13 is illustrated a modification wherein the tie bricks arearranged in staggered order.

It will be observed that in the typical setting illustrated in Figures9, 10, 11 and 12, vertical flues 6 by 9 inches, and horizontal lines 6%by 6% inches are formed, thereby ample area being provided and withoutsacrificing the exposed heating surfaces.

Resultant of the concave-concave formation of my improvedtie brick, is aheating surface that is exposed to both exhaust and incoming gases, anda greater turbulence in the gas stream the setting.

In the modiflcation as inFigure 13 whereinthe tiebricks are disposed instaggered order, there isrelatively increased surface exposure, andrelatively slightly decreased flue area. Figure 14 shows anothermodification of setting wherein the tie bricks are inmore closelystaggered order, to afford increased exposed surfaces, minimum i'iuearea, and a greater mass. In all instances wherein my invention is used,since all exposed surfaces are curvate, extremely slight resistance, ifany, is offered, to the particles in suspension being carried by thegases.

f A further advantage of my new tie brick is that it is self locking.There is suitable clearance F between the facing portions of the studsC. The

flanges B which overlap the proximate side faces of .the line bricks,efiectively hold the latter against dislodgement 'or shifting, wherebyvigorus cleaning of the exposed surfaces, as by a suitable blow pipe orlance, is practicable, and without liability of dislodging the brick.

Since the larger part of the complete setting in which my improved tiebricks are embodied,

is composed of the conventional rectangular checker bricks, the slightincrease oi cost over the use of conventional bricks throughout isinconsiderable, whereas all other forms of special checker bricks areincapable of being used in combination with bricks of conventional formandcost.

A reg'enerator chamberembodying a checker "brick installation inaccordance with my invention is of efliciency to measure up to theincreased present day 'efliciency of the melting and refining chamberstructure, thus contributing to uninterrupted furnace operation, andmaintenance 01., ignition temperatures at all times.

My improved spool shaped tie brick may be positioned to provide amplevertical flues six and .one half by nine inches where excessive batchcarry-over is encountered; or it may be positioned in staggered orderforming flues six and one half inches in diameter suitable when wastegases are comparatively freefrom particles in suspension. A settingembodying my improved tie blocks provides horizontal iiues ofsix and onehalf inches in diameter on nine inch centers both directions, thusassuring ample space for the use of a cleaning lance. In the use of mytie brick,

the spacing of the line bricks to allow for communicating passageways atlocations intermediate the'tie bricks is practicable. This arrangementisdesirable in instances where the regenerative chamber is accessible forcleaning under the ports or down takes.

In an installation comprising my improved tie bricks, the area of theexposed surfaces is somewhat greater than the area of exposed surfacesof transverse conventional bricks, for a given flue area, and is alsoconsiderably greater in mass.

My improved tie bricks may be composed of first quality or of super"quality fire clay, or oi silica. They require no engineering service,.and they can be set by the exercise of only ordinary skill. Whereasthey do, notconstitute a rigidly locked mass, they cannot easily bedislodged, and may be lanced as often as may be desired without injury.By virtue of their contour they facilitate the business of lancing byconstituting a cradle upon which the lance may be more expeditiouslymanipulated.

Whereas I have described my invention as being'especially applicable tofurnaces intended tor use in the industry of glass making. it will beunderstoodthat it is applicable as well to furnaces or ovens of theregenerative type as used in baking and annealing processes, and inother industries such as steel making and the like. Also it will beunderstood that my improved installation and tie brick is subject tominor modifications and changes which might be suggested by thoseskilled in the art to which my invention appertains, without departingfrom the principle of my invention or sacrificing any of its advantages.

- What I claim as my invention is:

1. A regenerator installation comprising line bricks arranged inalignment one row'above another, the bricks of one or more rows beingspaced, and spool shaped concave-concave tie bricks each embodying ateach of its ends a stud rectangular in cross section and that is reposedbetween the edges oi the facing ends of the spaced line bricks.

2..A checker brick consisting 01 a refractory unitoi spool shapedconcavo-concave formation,

each end thereof embodying a stud rectangular

